This invention relates generally to switches which are activateable to control access to secured areas. More particularly, this invention relates to key operated switches employed in high security systems.
In devices to which the invention relates, a key operated switch is employed to open or close an electrical switch which sends a signal to a security system. The signal may, for example, allow limited access, prevent access or, depending on additional factors, provide selective access to a secured area. The signal may be high or low and accordingly may be termed a xe2x80x9cmomentaryxe2x80x9d transmittal or may have a duration for an extended period of time which may be termed a xe2x80x9cmaintainxe2x80x9d mode. For some related switch devices, there may be multiple switch settings at various angular positions of the key upon rotation. In highly sophisticated security systems capable of a wide variety of security functions, numerous switches may be employed. Each of the switches may require a specific configuration for a given function, location or signal component of the integrated security system.
Briefly stated, the invention in a preferred form is a high security switch which incorporates an efficient system for implementing a momentary and/or maintain switch modes. The high security switch comprises a cam operator which is mounted in fixed rotatable relationship with a plug of a lock cylinder. A pendulum-like arm is pivotably mounted relative to a base for the lock cylinder. A magnet is carried by the arm. A second magnet is mounted in a fixed relationship with respect to the base and alignable with the first magnet upon pivotable movement of the arm to define a first mode, i.e., momentary or maintain mode, which is defined by the relative polarities of the opposed magnets. In the maintain mode, the arm is pivotably maintained in a given angular position under the magnetic attraction of the magnets. In the momentary mode, the magnets repel and the arm pivotably moves from a position wherein the first and second magnets align. The switch may employ magnets to provide a momentary and maintain mode at spaced angular positions upon selective directional rotation of the key. In one embodiment, a pair of electrical switches, each having two states, is mounted to a panel. The arm carries a pin which engages one or the other of the electrical switches to close the switch contacts.
In accordance with the invention, a method is also provided for setting the operate characteristics of a multi-positional switch wherein switch positions are defined by a pair of opposing poles of magnets. The method may also comprise providing an extractor having a magnetic field strength which is greater than that of the magnets, magnetically bonding the extractor to the magnet, removing the bonded magnet from the switch assembly and inserting a magnet having a selective polarity orientation into the assembly. The method step may essentially comprise merely reversing the orientation of the magnet.
An object of the invention is to provide a new and improved switch for a high security system.
Another object of the invention is to provide a new and improved high security switch having an efficient and reliable operation.
A further object of the invention is to provide a new and improved high security switch that does not require a mechanical spring return mechanism or a mechanical spring for indexing at a given switch position.
A yet further object of the invention is to provide a new and improved high security switch which may be custom configured in the field for a wide range of signal functions in a highly efficient and reliable installation process.